System for manufacturing liquid crystal display device

ABSTRACT

A system for manufacturing a liquid crystal display device, comprising a panel turning mechanism that has: a long side-supporting part for supporting the liquid crystal panel by coming into contact with an end face along at least one long side of the liquid crystal panel; and a short side-supporting part for supporting the liquid crystal panel by coming into contact with an end face along at least one short side of the liquid crystal panel and is configured to turn over the liquid crystal panel about an axis not parallel to any of the long and short sides of the liquid crystal panel in such a manner that the positional relationship between the long and short sides is reversed while both the long and short sides are supported.

CROSS-REFERENCE OF RELATED APPLICATIONS

This application is a Divisional of application Ser. No. 13/038,076,filed Mar. 1, 2011, which claims priority of Japanese Patent ApplicationNos. 2010-222035 and 2010-246501, the contents of which are incorporatedherein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a system and a method for manufacturing aliquid crystal display device by bonding sheet pieces of opticalfunctional films including polarizing films to both surfaces of arectangular liquid crystal panel.

2. Description of the Related Art

A known example of a liquid crystal display device manufacturing systemas mentioned above is configured to turn over a substrate 1 to which apiece 19A of a belt-shaped film 10A has been bonded and then to bond apiece 19B of another belt-shaped film 10B to the substrate 1 (see forexample Japanese Patent Application Laid-Open (JP-A) No. 2005-37417,paragraphs [0037] to [0044] and FIGS. 6 to 9).

On the other hand, there has been a demand for a compact manufacturingline that can maintain a high level of bonding accuracy and performanceeven when rolls with different widths corresponding to the long andshort sides of a rectangular liquid crystal panel are used in it. Tomeet such a demand, another proposal is made which includes rotating aliquid crystal panel by 90° so that a linear manufacturing line can beprovided (see for example Japanese Patent No. 4307510).

PRIOR ART LITERATURE Patent Document

-   Patent Document 1: Japanese Patent Application Laid-Open (JP-A) No.    2005-37417-   Patent Document 2: Japanese Patent No. 4307510 Publication

When a liquid crystal display device is manufactured by bonding opticalfunctional films to both surfaces of a liquid crystal panel, a turningmechanism for turning over the liquid crystal panel and a rotationmechanism for rotating it may be provided so that each opticalfunctional film can be bonded from only one of the upper side or thelower side and that a linear manufacturing line can be provided.

When the steps of turning over a liquid crystal panel and rotating itare each independently performed, the liquid crystal panel should beturned over about an axis parallel to the long or short side of theliquid crystal panel in order not to change the positional relationshipbetween the long and short sides before and after the turnover. In thiscase, however, the weight of the liquid crystal panel is applied to onlyone of the long or short side of the liquid crystal panel during theturnover, so that the liquid crystal panel may crack or chip. Inparticular, as liquid crystal displays increasingly become wider, liquidcrystal panels become more likely to crack or chip.

SUMMARY OF THE INVENTION

The invention has been made under the circumstances described above, andan object of the invention is to provide a system and a method formanufacturing a liquid crystal display device, which can put a liquidcrystal panel into a turned over and rotated state in a moresatisfactory manner. Another object of the invention is to provide asystem and a method for manufacturing a liquid crystal display device,which can improve the accuracy with which optical functional films arebonded to a liquid crystal panel.

A system for manufacturing a liquid crystal display device according tothe present invention relates to a system for manufacturing a liquidcrystal display device by bonding sheet pieces of optical functionalfilms comprising polarizing films to both surfaces of a rectangularliquid crystal panel, comprising:

a panel turning mechanism for turning over the liquid crystal panelafter one of the sheet pieces of optical functional films is bonded tothe liquid crystal panel and before another of the sheet pieces ofoptical functional films is bonded thereto, wherein

the panel turning mechanism has: a long side-supporting part forsupporting the liquid crystal panel by coming into contact with an endface along at least one long side of the liquid crystal panel; and ashort side-supporting part for supporting the liquid crystal panel bycoming into contact with an end face along at least one short side ofthe liquid crystal panel, and

the panel turning mechanism turns over the liquid crystal panel about asingle axis neither parallel to the long side of the liquid crystalpanel nor to the short side of the liquid crystal panel in such a mannerthat the positional relationship between the long and short sides of theliquid crystal panel is reversed.

According to an embodiment of the invention, when the liquid crystalpanel is turned over about a single axis not parallel to any of the longand short sides of the liquid crystal panel with both of the long andshort sides being supported, the weight of the liquid crystal panel canbe dispersed to both of the long and short sides for the reversal of thepositional relationship between the long and short sides of the liquidcrystal panel. Therefore, the liquid crystal panel is less likely tocrack or chip, and the liquid crystal panel can be put into a turnedover and rotated state in a more satisfactory manner.

In particular, the long and short sides of the liquid crystal panel canbe aligned at the same time, because the long-side-end-face andshort-side-end-face of the liquid crystal panel are brought into contactwith the long side-supporting part and the short side-supporting part,respectively. Therefore, the directions of the long and short sides canbe aligned with higher accuracy with respect to the feed direction ofthe liquid crystal panel, so that the optical functional films can bebonded to the liquid crystal panel with improved accuracy.

It is preferable that the long side-supporting part comes into contactwith only an end face along one long side of the liquid crystal panel tosupport the liquid crystal panel, and

the short side-supporting part comes into contact with only an end facealong one short side of the liquid crystal panel to support the liquidcrystal panel.

According to an embodiment of the invention, the liquid crystal panelcan be successfully supported, not depending on the size of the liquidcrystal panel. Specifically, a structure configured to support end facesalong both long or short sides of a liquid crystal panel cannot supportanother liquid crystal panel of a size larger than the distance betweenthe long side-supporting parts or the short side-supporting parts. Incontrast, a structure configured to support only an end face along onelong side and an end face along one short side according to anembodiment of the invention can successfully support even a larger sizeliquid crystal panel. Therefore, such a structure makes it possible toturn over different size liquid crystal panels in the same panel turningmechanism.

In addition, the structure configured to support end faces along bothlong or short sides of a liquid crystal panel may cause a force to acton the liquid crystal panel from the opposed long side-supporting partsor the opposed short side-supporting parts, so that an excessive loadmay be applied to the liquid crystal panel to cause cracking, chippingor bending of the liquid crystal panel. In contrast, the structureconfigured to support only an end face along one long side and an endface along one short side according to an embodiment of the inventioncan prevent such problems. This advantageous effect becomes moresignificant as the size of the liquid crystal panel increases.

In addition, when the liquid crystal panel is supported only at an endface along one long side and at an end face along one short sideaccording to an embodiment of the invention, the long side-supportingpart and the short side-supporting part only have to be in contact withthese end faces, so that the time required to support the liquid crystalpanel can be reduced as much as possible, which can increase theproduction efficiency. In contrast, the structure configured to supportend faces along both long or short sides of a liquid crystal panelrequires a process including bringing the long side-supporting part orthe short side-supporting part into contact with one end face along onelong or short side and then bringing the long side-supporting part orthe short side-supporting part into contact with the other end facealong the other long or short side, which increases the number of stepsand the time required to support the liquid crystal panel.

It is preferable that the long side-supporting part comes into contactwith only an end face along a long side of the liquid crystal panel tosupport the liquid crystal panel, wherein the long side is closer to thesingle axis, and

the short side-supporting part comes into contact with only an end facealong a short side of the liquid crystal panel to support the liquidcrystal panel, wherein the short side is closer to the single axis.

According to an embodiment of the invention, the liquid crystal panelcan be turned over while the liquid crystal panel is supported at an endface along one long side and at an end face along one short side by thelong side-supporting part and the short side-supporting part,respectively, from the lower side, so that the liquid crystal panel isprevented from interfering with the liquid crystal panel-feeding line.

It is preferable that the panel turning mechanism has a bothsurface-contact part for coming into contact with at least part of bothsurfaces of the liquid crystal panel.

According to an embodiment of the invention, the liquid crystal panelcan be successfully held and stably turned over with the bothsurface-contact part being in contact with both surfaces of the liquidcrystal panel.

It is preferable that the panel turning mechanism turns over the liquidcrystal panel about an axis inclined by 45° from a direction of feedingof the liquid crystal panel to a direction parallel to the surface ofthe liquid crystal panel.

According to an embodiment of the invention, the positional relationshipbetween the long and short sides of the liquid crystal panel can beeasily reversed only by turning over the liquid crystal panel about theaxis inclined by 45°.

The system can be for manufacturing the liquid crystal display device bya process comprising feeding optical functional films from first andsecond continuous rolls with different widths, respectively, which areeach formed by winding, into a roll, a long optical functional filmcomprising a polarizing film, transversely cutting the opticalfunctional films to form sheet pieces of the optical functional films,and bonding the sheet pieces to both surfaces of the rectangular liquidcrystal panel.

The system can be for manufacturing the liquid crystal display device bya process comprising feeding sheet pieces of optical functional filmsand carrier films from first and second continuous rolls with differentwidths, respectively, which are each formed by winding, into a roll, alaminate comprising a carrier film and sheet pieces of an opticalfunctional film comprising a polarizing film, peeling off the sheetpieces of the optical functional films from the carrier films, andbonding the sheet pieces to both surfaces of the rectangular liquidcrystal panel.

A method for manufacturing a liquid crystal display device according tothe present invention relates to a method for manufacturing a liquidcrystal display device by bonding sheet pieces of optical functionalfilms comprising polarizing films to both surfaces of a rectangularliquid crystal panel, comprising:

a panel turning step comprising turning over the liquid crystal panelafter one of the sheet pieces of optical functional films is bonded tothe liquid crystal panel and before another of the sheet pieces ofoptical functional films is bonded thereto, wherein

in the panel turning step, the liquid crystal panel is turned over abouta single axis neither parallel to a long side of the liquid crystalpanel nor to a short side of the liquid crystal panel in such a mannerthat the positional relationship between the long and short sides of theliquid crystal panel is reversed using a panel turning mechanismcomprising: a long side-supporting part for supporting the liquidcrystal panel by coming into contact with an end face along at least onelong side of the liquid crystal panel; and a short side-supporting partfor supporting the liquid crystal panel by coming into contact with anend face along at least one short side of the liquid crystal panel.

It is preferable that the long side-supporting part comes into contactwith only an end face along one long side of the liquid crystal panel tosupport the liquid crystal panel, and

the short side-supporting part comes into contact with only an end facealong one short side of the liquid crystal panel to support the liquidcrystal panel.

It is preferable that the long side-supporting part comes into contactwith only an end face along a long side of the liquid crystal panel tosupport the liquid crystal panel, wherein the long side is closer to thesingle axis, and

the short side-supporting part comes into contact with only an end facealong a short side of the liquid crystal panel to support the liquidcrystal panel, wherein the short side is closer to the single axis.

It is preferable that the panel turning mechanism has a bothsurface-contact part for coming into contact with at least part of bothsurfaces of the liquid crystal panel.

It is preferable that, in the panel turning step, the liquid crystalpanel is turned over about an axis inclined by 45° from a direction offeeding of the liquid crystal panel to a direction parallel to thesurface of the liquid crystal panel.

The method can be for manufacturing the liquid crystal display device bya process comprising feeding optical functional films from first andsecond continuous rolls with different widths, respectively, which areeach formed by winding, into a roll, a long optical functional filmcomprising a polarizing film, transversely cutting the opticalfunctional films to form sheet pieces of the optical functional films,and bonding the sheet pieces to both surfaces of the rectangular liquidcrystal panel.

The method can be for manufacturing the liquid crystal display device bya process comprising feeding sheet pieces of optical functional filmsand carrier films from first and second continuous rolls with differentwidths, respectively, which are each formed by winding, into a roll, alaminate comprising a carrier film and sheet pieces of an opticalfunctional film comprising a polarizing film, peeling off the sheetpieces of the optical functional films from the carrier films, andbonding the sheet pieces to both surfaces of the rectangular liquidcrystal panel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow chart showing an example of the liquid crystal displaydevice manufacturing method according to an embodiment of the invention;

FIG. 2 is a schematic plan view showing an example of the liquid crystaldisplay device manufacturing system;

FIG. 3 is a schematic side view showing a process of bonding a firstoptical functional film to a liquid crystal panel;

FIG. 4 is a schematic side view showing a process of bonding a secondoptical functional film to the liquid crystal panel;

FIG. 5 is a cross-sectional view showing an example of the process ofbonding optical functional films to a liquid crystal panel;

FIG. 6 is a schematic perspective view showing an example of the methodof turning over a liquid crystal panel using a panel turning mechanism;

FIG. 7 is a schematic plan view showing an example of the panel turningmechanism;

FIG. 8 is a schematic perspective view showing another example of themethod of turning over a liquid crystal panel using a panel turningmechanism;

FIG. 9 is a schematic perspective view showing a further example of themethod of turning over a liquid crystal panel using a panel turningmechanism;

FIG. 10 is a schematic perspective view showing a further example of themethod of turning over a liquid crystal panel using a panel turningmechanism;

FIG. 11 is a schematic perspective view showing a further example of themethod of turning over a liquid crystal panel using a panel turningmechanism;

FIG. 12 is a schematic perspective view showing a further example of themethod of turning over a liquid crystal panel using a panel turningmechanism;

FIG. 13 is a schematic perspective view showing a further example of themethod of turning over a liquid crystal panel using a panel turningmechanism;

FIG. 14A is a diagram showing an example of how a panel turningmechanism comes into contact with the surface of a liquid crystal panelwhen it supports the liquid crystal panel;

FIG. 14B is a diagram showing another example of how a panel turningmechanism comes into contact with the surface of a liquid crystal panelwhen it supports the liquid crystal panel;

FIG. 14C is a diagram showing a further example of how a panel turningmechanism comes into contact with the surface of a liquid crystal panelwhen it supports the liquid crystal panel;

FIG. 14D is a diagram showing a further example of how a panel turningmechanism comes into contact with the surface of a liquid crystal panelwhen it supports the liquid crystal panel;

FIG. 14E is a diagram showing a further example of how a panel turningmechanism comes into contact with the surface of a liquid crystal panelwhen it supports the liquid crystal panel;

FIG. 15A is a schematic plan view showing an example of which part of aliquid crystal panel is supported by a panel turning mechanism;

FIG. 15B is a schematic plan view showing another example of which partof a liquid crystal panel is supported by a panel turning mechanism;

FIG. 15C is a schematic plan view showing a further example of whichpart of a liquid crystal panel is supported by a panel turningmechanism;

FIG. 15D is a schematic plan view showing a further example of whichpart of a liquid crystal panel is supported by a panel turningmechanism;

FIG. 15E is a schematic plan view showing a further example of whichpart of a liquid crystal panel is supported by a panel turningmechanism;

FIG. 15F is a schematic plan view showing a further example of whichpart of a liquid crystal panel is supported by a panel turningmechanism;

FIG. 15G is a schematic plan view showing a further example of whichpart of a liquid crystal panel is supported by a panel turningmechanism;

FIG. 15H is a schematic plan view showing a further example of whichpart of a liquid crystal panel is supported by a panel turningmechanism; and

FIG. 15I is a schematic plan view showing a further example of whichpart of a liquid crystal panel is supported by a panel turningmechanism.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 is a flow chart showing an example of the liquid crystal displaydevice manufacturing method according to an embodiment of the invention.FIG. 2 is a schematic plan view showing an example of the liquid crystaldisplay device manufacturing system. FIG. 3 is a schematic side viewshowing a process of bonding a first optical functional film F11 to aliquid crystal panel W. FIG. 4 is a schematic side view showing aprocess of bonding a second optical functional film F21 to the liquidcrystal panel W.

Liquid Crystal Panel

The liquid crystal panel W for use in the liquid crystal display devicemanufactured according to the invention is typically a glass substrateunit including a pair of glass substrates and a liquid crystal placedtherebetween. The liquid crystal panel W has a rectangular shape.

Optical Functional Film

The optical functional film for use in the liquid crystal display devicemanufactured according to the invention includes a polarizing film. Apressure-sensitive adhesive layer is formed on one side of the opticalfunctional film so that it can be bonded to the liquid crystal panel W,and a carrier film for protecting the pressure-sensitive adhesive layeris also provided thereon. Namely, the optical functional film, thepressure-sensitive adhesive layer, and the carrier film are stacked inthis order. A surface protecting film is provided on the other side ofthe optical functional film with a pressure-sensitive adhesive layerinterposed therebetween. Hereinafter, the laminate of the surfaceprotecting film, the optical functional film, and the carrier film isalso referred to as an optical film laminate.

FIG. 5 is a cross-sectional view showing an example of the process ofbonding the optical functional film to the liquid crystal panel W. Inthis embodiment, first and second optical film laminates F1 and F2 areused. The first optical film laminate F1 is to be bonded to one surfaceof the liquid crystal panel W and includes a first optical functionalfilm F11, and the second optical film laminate F2 is to be bonded to theother surface of the liquid crystal panel W and includes a secondoptical functional film F21.

The first optical film laminate F1 has a structure in which the firstoptical functional film F11, a first carrier film F12 and a surfaceprotecting film F13 are stacked. In this embodiment, the first opticalfunctional film F11 includes a polarizing film. The first opticalfunctional film F11 includes a first polarizer F11 a, a first film F11 bbonded to one side thereof with an adhesive layer (not shown) interposedtherebetween, and a second film F11 c bonded to the other side thereofwith an adhesive layer (not shown) interposed therebetween. The firstpolarizer F11 a is typically formed by stretching a polyvinyl alcohol(PVA) film. It will be understood that the first polarizer F11 a may beformed using any other film than the polyvinyl alcohol film.

The first and second films F11 b and F11 c are each typically aprotective film (such as a triacetylcellulose film or a PET film). Thesecond film F11 c will be bonded to the liquid crystal panel W with afirst pressure-sensitive adhesive layer F14 interposed therebetween. Thefirst film F11 b may be subjected to a surface treatment. For example,the surface treatment may be a hard coating treatment, an antireflectiontreatment, or a treatment for any other purpose such as ananti-sticking, diffusion, or antiglare purpose. The first carrier filmF12 is bonded to the second film F11 c with the first pressure-sensitiveadhesive layer F14 interposed therebetween. The surface protecting filmF13 is bonded to the first film F11 b with a pressure-sensitive adhesivelayer F15 interposed therebetween.

The laminated structure of the second optical film laminate F2 is thesame as, but not limited to, that of the first optical film laminate F1.The second optical film laminate F2 has a structure in which a secondoptical functional film F21, a second carrier film F22, and a surfaceprotecting film F23 are stacked. In this embodiment, the second opticalfunctional film F21 includes a polarizing film. The second opticalfunctional film F21 includes a second polarizer F21 a, a third film F21b bonded to one side thereof with an adhesive layer (not shown)interposed therebetween, and a fourth film F21 c bonded to the otherside thereof with an adhesive layer (not shown) interposed therebetween.The second polarizer F21 a is typically formed by drying a polyvinylalcohol (PVA) film. It will be understood that the second polarizer F21a may be formed using any other film than the polyvinyl alcohol film.

The third and fourth films F21 b and F21 c are each typically aprotective film (such as a triacetylcellulose film or a PET film). Thefourth film F21 c will be bonded to the liquid crystal panel W with asecond pressure-sensitive adhesive layer F24 interposed therebetween.The third film F21 b may be subjected to a surface treatment. Forexample, the surface treatment may be a hard coating treatment, anantireflection treatment, or a treatment for any other purpose such asan anti-sticking, diffusion, or antiglare purpose. The second carrierfilm F22 is bonded to the fourth film F21 c with the secondpressure-sensitive adhesive layer F24 interposed therebetween. Thesurface protecting film F23 is bonded to the third film F21 b with apressure-sensitive adhesive layer F25 interposed therebetween.

Manufacturing Flow Chart

(1) Step of Providing First Continuous Roll (S1 in FIG. 1). A firstcontinuous roll R1 is provided which is formed by winding a first longoptical film laminate F1 into a roll. The first continuous roll R1 has awidth depending on the size of the liquid crystal panel W to be bonded.Specifically, the first continuous roll R1 is formed by winding, into aroll, a first optical film laminate F1 including a first opticalfunctional film F11 with a width corresponding to the short or long sideof the liquid crystal panel W. More specifically, the first continuousroll R1 is formed by winding, into a roll, the first long optical filmlaminate F1 that is obtained by slitting, into a width corresponding tothe short or long side of the liquid crystal panel W, a long materialincluding the first optical functional film F11, the firstpressure-sensitive adhesive layer F14, and the first carrier film F12stacked in this order. The polarizing film as a component of the longmaterial is preferably formed through stretching in the longitudinaldirection, and in such a case, the absorption axis of the polarizingfilm is formed along the longitudinal direction. Such a long materialshould be slit parallel to the longitudinal direction so that the firstoptical film laminate F1 formed can have an absorption axis extendingalong the longitudinal direction with high accuracy. In this embodiment,the first continuous roll R1 used has a width corresponding to the shortside of the liquid crystal panel W.

(2) Step of Feeding First Optical Functional Film (S2 in FIG. 1). Afirst feeder 12 draws and feeds the first optical film laminate F1including the first optical functional film F11 to the downstream sidefrom the first continuous roll R1 provided and placed. The first opticalfilm laminate F1 is fed from the first continuous roll R1 linearly inplanar view.

(3) First Inspection Step (S3 in FIG. 1). The first optical filmlaminate F1 is inspected for defects using a first defect inspectionapparatus 14. In this step, the defect inspection method may be a methodof performing imaging and image processing on both sides of the firstoptical film laminate F1 with transmitted light or reflected light, amethod of performing imaging and image processing with a polarizing filmfor inspection arranged in a crossed Nicols relationship (also referredto as “0° cross”) with the absorption axis of the polarizing film (theobject to be inspected) between a CCD camera and the object, or a methodof performing imaging and image processing with a polarizing film forinspection arranged at a certain angle (for example, in the range ofmore than 0° to 10°, also referred to as “X° cross”) with the absorptionaxis of the polarizing film (the object to be inspected) between a CCDcamera and the object. For example, gray-scale determination based onbinarization may be used in the image processing algorithm to detectdefects.

Defect information detected by the first defect inspection apparatus 14is associated with the positional information (such as positioncoordinates) and sent to a controller so that it can contribute to thecutting process with a first cutting apparatus 16.

(4) First Cutting Step (S4 in FIG. 1). The first cutting apparatus 16cuts, in the transverse direction, at least the first optical functionalfilm F11 of the first optical film laminate F1 drawn from the firstcontinuous roll R1, so that a sheet piece of the first opticalfunctional film F11 is formed. In this example, while the first carrierfilm F12 is left uncut, the first optical functional film F11, to whichthe first carrier film F12 is attached, and the surface protecting filmF13, to which the first optical functional film F11 is attached, are cutinto a predetermined size. It will be understood that such a process isnon-limiting, and alternatively, for example, the first optical filmlaminate F1 may be cut completely so that a piece of the first opticalfilm laminate F1 can be formed. For example, the cutting means may be alaser, a cutter, or the like. The cutting is preferably performed basedon the defect information detected by the first defect inspectionapparatus 14 so that defects can be avoided. This significantlyincreases the first optical film laminate F1 yield. Defective parts ofthe first optical film laminate F1 are removed by a first removingapparatus (not shown) so as not to be bonded to the liquid crystal panelW. In this embodiment, the first optical functional film F11 is cut intoa length corresponding to the long side of the liquid crystal panel W.Alternatively, however, it may be cut into a length corresponding to theshort side of the liquid crystal panel W when the first continuous rollR1 has a width corresponding to the long side of the liquid crystalpanel W.

All of the step of providing the first continuous roll, the firstinspection step, and the first cutting step are preferably performed ina continuous manufacturing line. In the above series of manufacturingsteps, a sheet piece of the first optical functional film F11 is formed,which is to be bonded to one surface of the liquid crystal panel W. Adescription is given below of a process of forming a sheet piece of thesecond optical functional film F21 to be bonded to the other surface ofthe liquid crystal panel W.

(5) Step of Providing Second Continuous Roll (S11 in FIG. 1). A secondcontinuous roll R2 is provided which is formed by winding a second longoptical film laminate F2 into a roll. The second continuous roll R2 hasa width depending on the size of the liquid crystal panel W to bebonded. Specifically, the second continuous roll R2 is formed bywinding, into a roll, a second optical film laminate F2 including asecond optical functional film F21 with a width corresponding to thelong or short side of the liquid crystal panel W. More specifically, thesecond continuous roll R2 is formed by winding, into a roll, the secondlong optical film laminate F2 that is obtained by slitting, into a widthcorresponding to the long or short side of the liquid crystal panel W, along material including the second optical functional film F21, thesecond pressure-sensitive adhesive layer F24, and the second carrierfilm F22 stacked in this order. The polarizing film as a component ofthe long material is preferably formed through stretching in thelongitudinal direction, and in such a case, the absorption axis of thepolarizing film is formed along the longitudinal direction. Such a longmaterial should be slit parallel to the longitudinal direction so thatthe second optical film laminate F2 formed can have an absorption axisextending along the longitudinal direction with high accuracy. Thesecond continuous roll R2 is typically formed with a width differentfrom that of the first continuous roll R1. Specifically, when the firstcontinuous roll R1 is formed with a width corresponding to the long sideof the liquid crystal panel W, the second continuous roll R2 is formedwith a width corresponding to the short side of the liquid crystal panelW, and when the first continuous roll R1 is formed with a widthcorresponding to the short side of the liquid crystal panel W, thesecond continuous roll R2 is formed with a width corresponding to thelong side of the liquid crystal panel W. In this embodiment, the secondcontinuous roll R2 used has a width corresponding to the long side ofthe liquid crystal panel W. As used herein, the expression“corresponding to the long or short side of the liquid crystal panel W”means that the bonding length of the optical functional film F11 or F21(exclusive of the length of the exposed portion) will correspond to thelength of the long or short side of the liquid crystal panel W and doesnot mean that the width of the optical functional film F11 or F21 has tobe equal to the length of the long or short side of the liquid crystalpanel W.

(6) Step of Feeding Second Optical Functional Film (S12 in FIG. 1). Asecond feeder 22 draws and feeds the second optical film laminate F2including the second optical functional film F21 to the downstream sidefrom the second continuous roll R2 provided and placed. The secondoptical film laminate F2 is fed from the second continuous roll R2linearly in planar view. More specifically, as shown in FIG. 2, thefirst and second optical film laminates F1 and F2 are fed from the firstand second continuous rolls R1 and R2, respectively, on first linearfeed paths P1 whose extended lines overlap each other in planar view(the film feeding step). The first and second optical film laminates F1and F2 may be fed in directions opposite to each other or in the samedirection on the first linear feed paths P1. In this embodiment, theliquid crystal display device manufacturing system includes film feedinglines L1 that are arranged so that the first and second optical filmlaminates F1 and F2 being fed can be linearly aligned with each other inplanar view as described above (see FIGS. 3 and 4).

(7) Second Inspection Step (S13 in FIG. 1). The second optical filmlaminate F2 is inspected for defects using a second defect inspectionapparatus 24. In this step, the defect inspection method is the same asthe above method with the first defect inspection apparatus 14. However,the first inspection step (S3) and the second inspection step (S13) maybe omitted. In such a case, the first and second optical film laminatesF1 and F2 may be inspected for defects at a stage where the first andsecond continuous rolls R1 and R2 are manufactured, and liquid crystaldisplay devices may be manufactured using the first and secondcontinuous rolls R1 and R2 to which the defect information detected bythe defect inspection has been attached.

(8) Second Cutting Step (S14 in FIG. 1). A second cutting apparatus 26cuts, in the transverse direction, at least the second opticalfunctional film F21 of the second optical film laminate F2 drawn fromthe second continuous roll R2, so that a sheet piece of the secondoptical functional film F21 is formed. In this example, while the secondcarrier film F22 is left uncut, the second optical functional film F21,to which the second carrier film F22 is attached, and the surfaceprotecting film F23, to which the second optical functional film F21 isattached, are cut into a predetermined size. It will be understood thatsuch a process is non-limiting, and alternatively, for example, thesecond optical film laminate F2 may be cut completely so that a piece ofthe second optical film laminate F2 can be formed. For example, thecutting means may be a laser, a cutter, or the like. The cutting ispreferably performed based on the defect information detected by thesecond defect inspection apparatus 24 so that defects can be avoided.This significantly increases the second optical film laminate F2 yield.Defective parts of the second optical film laminate F2 are removed by asecond removing apparatus (not shown) so as not to be bonded to theliquid crystal panel W. In this embodiment, the second opticalfunctional film F21 is cut into a length corresponding to the short sideof the liquid crystal panel W. Alternatively, however, it may be cutinto a length corresponding to the long side of the liquid crystal panelW when the second continuous roll R2 has a width corresponding to theshort side of the liquid crystal panel W.

The step of feeding the liquid crystal panel W is performed in parallelwith the step of forming sheet pieces of the first and second opticalfunctional films F11 and F21, respectively. The liquid crystal panel Wis subjected to the process described below while it is fed.

(9) Cleaning Step (S6 in FIG. 1). The surface of the liquid crystalpanel W is cleaned by polishing cleaning, washing with water, or anyother cleaning method. As shown in FIGS. 3 and 4, the liquid crystalpanel W having undergone cleaning is fed on a second linear feed path P2in a panel feeding line L2 that is placed above the film feeding linesL1 in an overlapping manner, and is placed to feed the liquid crystalpanels W linearly in planar view (the panel feeding step). The secondlinear feed path P2 extends at least between first and second bondingapparatuses 18 and 28 and placed parallel to the first linear feed pathsP1 so as to at least partially overlap with the first linear feed pathsP1 in planar view (see FIG. 2).

(10) Step of Bonding First Optical Functional Film (S5 in FIG. 1). Thecut piece of the first optical functional film F11 (the sheet piece ofthe first optical functional film F11) is bonded to one surface of theliquid crystal panel W with the pressure-sensitive adhesive layer F14interposed therebetween by the first bonding apparatus 18, while thefirst carrier film F12 is peeled off. The first carrier film F12 peeledoff by a peeling unit 171 is wound onto a roll 172. In the bonding, thefirst optical functional film F11 and the liquid crystal panel W areinserted and press-bonded between a pair of rollers 181 and 182 opposedto each other.

(11) Step of Transporting and Feeing Panel (S7 in FIG. 1). The liquidcrystal panel W to which the sheet piece of the first optical functionalfilm F11 has been bonded by the first bonding apparatus 18 is fed to asecond bonding apparatus 28 along the second linear feed path P2. Thepanel feeding line L2 is provided with a panel turning mechanism 200 forturning over the liquid crystal panel W after the sheet piece of thefirst optical functional film F11 is bonded thereto and before a sheetpiece of the second optical functional film F21 is bonded thereto. Thepanel turning mechanism 200 turns over the liquid crystal panel W sothat the positional relationship between the long and short sides of theliquid crystal panel W can be reversed (the step of turning over thepanel). Specifically, the long side of the liquid crystal panel W afterthe turnover is parallel to the short side before the turnover, and theshort side of the liquid crystal panel W after the turnover is parallelto the long side before the turnover. The panel turning mechanism 200puts the liquid crystal panel W into a turned over state and into ahorizontally rotated state by 90° to allow the first and second opticalfunctional films F11 and F21 to be bonded in a crossed Nicolsrelationship (in such a relationship that the absorption axes of thepolarizing films are perpendicular to each other) to the liquid crystalpanel W.

In the embodiment described above, the liquid crystal panel W is turnedover after the first optical functional film F11 is bonded thereto inthe first bonding apparatus 18. Alternatively, however, the secondoptical functional film F21 may be bonded to the liquid crystal panel Wbefore the first optical functional film F11 is bonded thereto asmentioned above. In such a case, the liquid crystal panel W may beturned over after the second optical functional film F21 is bondedthereto in the second bonding apparatus 28.

(12) Step of Bonding Second Optical Functional Film (S15 in FIG. 1). Thecut piece of the second optical functional film F21 (the sheet piece ofthe second optical functional film F21) is bonded to the other surfaceof the liquid crystal panel W with the pressure-sensitive adhesive layerF24 interposed therebetween by the second bonding apparatus 28, whilethe second carrier film F22 is peeled off. The second carrier film F22peeled off by a peeling unit 271 is wound onto a take-up roll 272. Inthe bonding, the second optical functional film F21 and the liquidcrystal panel W are inserted and press-bonded between a pair of rollers281 and 282 opposed to each other.

(13) Step of Inspecting Liquid Crystal Panel (S16 in FIG. 1). The liquidcrystal panel W with both surfaces bonded to the optical functionalfilms F11 and F21 is inspected using an inspection apparatus. An exampleof the inspection method is a method of performing imaging and imageprocessing on both sides of the liquid crystal panel W with transmittedlight and reflected light. Another example of the method uses apolarizing film for inspection placed between a CCD camera and theobject to be inspected. For example, gray-scale determination based onbinarization may be used in the image processing algorithm to detectdefects.

(14) Defect information detected by the inspection apparatus is used todetermine whether the liquid crystal panel W is non-defective. Theliquid crystal panel W determined to be non-defective is transferred tothe next implementing step. When determined to be defective, it issubjected to a reworking process, in which a new optical functional filmF11 or F21 is bonded, and then the product is inspected. The productdetermined to be non-defective is transferred to the implementing step,but the product determined to be defective is subjected to the reworkingprocess again or to disposal.

In the above series of manufacturing steps, the first optical functionalfilm F11 bonding step and the second optical functional film F21 bondingstep may be performed in a continuous manufacturing line, which makes itpossible to manufacture the liquid crystal display device in asatisfactory manner.

A description has been given of a method that includes leaving thecarrier films F12 and F22 uncut and cutting other components of theoptical film laminates F1 and F2 (half-cutting method). However, such amethod is non-limiting, and alternatively, for example, continuous rollshaving undergone half-cutting may be used, in which sheet pieces of theoptical functional films F11 and F21 formed by previously cutting theother components of the optical film laminates F12 and F22 than thecarrier films F12 and F22 are held on the carrier films F12 and F22,respectively. In this case, the continuous rolls may be formed by aprocess that includes slitting a long material into a widthcorresponding to the short or long side of the rectangular liquidcrystal panel W, cutting the optical functional films F11 and F21 andthe pressure-sensitive adhesive layers F14 and F24 of the resulting longoptical film laminates F1 and F2, respectively, into a lengthcorresponding to the long or short side of the liquid crystal panel W,while leaving the carrier films F12 and F22 uncut, and winding, intorolls, the laminates F1 and F2 having undergone the cutting,respectively. The optical film laminates F1 and F2 are drawn from suchcontinuous rolls, respectively, and the sheet pieces of the opticalfunctional films F11 and F21 are bonded to the surfaces of the liquidcrystal panel W with the pressure-sensitive adhesive layers F14 and F24interposed therebetween, respectively, while the carrier films F12 andF22 are peeled off, so that a liquid crystal display device ismanufactured. The optical functional films F11 and F21 do not alwayshave to be bonded after they are cut, and the cutting may be performedduring or after the bonding.

In this embodiment, a partition structure 50 is provided, and aircirculation apparatuses 40 for circulating air in the partitionstructure 50 are provided at the top of the partition structure 50. Inthis embodiment, the air circulation apparatuses 40 blow air into thepartition structure 50, and the blown air is allowed to flow from theupper side to the lower side in the partition structure 50 anddischarged from openings 50 a formed at the bottom of the partitionstructure 50. Thus, the air is circulated in the partition structure 50to keep the inside of the partition structure 50 clean.

FIG. 6 is a schematic perspective view showing an example of the methodof turning over the liquid crystal panel W using the panel turningmechanism 200. FIG. 7 is a schematic plan view showing an example of thepanel turning mechanism 200. It will be understood that the structure ofthe panel turning mechanism 200 is not limited to that shown in FIG. 7and, any of various other structures may be used to form the panelturning mechanism 200.

In this embodiment, the liquid crystal panel W is turned over about asingle axis A1 that is not parallel to any of the long and short sidesof the liquid crystal panel W. The axis A1 is inclined by 45° from thedirection of feeding of the liquid crystal panel W along the secondlinear feed path P2 to the direction parallel to the surface of theliquid crystal panel W.

As shown in FIG. 7, for example, the panel turning mechanism 200 has along side-supporting part 201 for supporting at least one long side ofthe liquid crystal panel W and a short side-supporting part 202 forsupporting at least one short side of the liquid crystal panel W. Inthis embodiment, the long side-supporting part 201 is configured tosupport only one long side of the liquid crystal panel W, and the longside-supporting part 201 is formed with a long-side-end-face contactpart 203 to be in contact with the end face of the liquid crystal panelW along its long side. In this embodiment, the short side-supportingpart 202 is configured to support only one short side of the liquidcrystal panel W, and the short side-supporting part 202 is formed with ashort-side-end-face contact part 204 to be in contact with the end faceof the liquid crystal panel W along its short side. It will beappreciated that the long side-supporting part 201 may be configured tosupport both long sides of the liquid crystal panel W or the shortside-supporting part 202 may be configured to support both short sidesof the liquid crystal panel W.

According to this embodiment, when the liquid crystal panel W is turnedover about the axis A1 not parallel to any of the long and short sidesof the liquid crystal panel W with both of the long and short sides ofthe liquid crystal panel W being supported, the weight of the liquidcrystal panel W can be dispersed to both of the long and short sides ofthe liquid crystal panel W for the reversal of the positionalrelationship between the long and short sides of the liquid crystalpanel W. Therefore, the liquid crystal panel W is less likely to sufferfrom cracking or chipping, and the liquid crystal panel W can be putinto a turned over and rotated state in a more satisfactory manner.

Particularly in this embodiment, the long and short sides of the liquidcrystal panel W can be aligned at the same time, because thelong-side-end-face and short-side-end-face of the liquid crystal panel Ware brought into contact with the long-side-end-face contact part 203and the short-side-end-face contact part 204, respectively. Therefore,even if the long and short sides of the liquid crystal panel W beingtransported are misaligned, the long-side-end-face andshort-side-end-face of the liquid crystal panel W can be aligned bybringing them into contact with the long-side-end-face andshort-side-end-face contact parts 203 and 204, respectively. Thus, thedirections of the long and short sides of the liquid crystal panel W canbe aligned with higher accuracy with respect to the feed direction, sothat the optical functional films F11 and F21 can be bonded to theliquid crystal panel W with improved accuracy.

As shown in the example in FIG. 7, the panel turning mechanism 200preferably has both side-contact parts 205 to be in contact with atleast part of both sides of the liquid crystal panel W. According tothis feature, the liquid crystal panel W can be held in a favorablemanner with both sides thereof being in contact with the bothside-contact part 205 and turned over in a stable manner. In thisexample, a plurality of both side-contact parts 205 are formed to extendparallel to one another on both one and the other surface sides of theliquid crystal panel W so that part of each surface can be in contactwith the both side-contact part 205. It will be understood that such astructure is non-limiting and any of various other structures may beused for the both side-contact part 205. For example, the bothside-contact part 205 may be configured to be in contact with the wholeof at least one surface of the liquid crystal panel W.

In the example shown in FIG. 6, the liquid crystal panel W is turnedover about an axis A1 passing through a corner portion of the liquidcrystal panel W. For example, the axis A1 is defined to pass through thecorner portion located on a downstream side with respect to the feeddirection of the liquid crystal panel W. According to this feature, inthe feed direction, the center of the liquid crystal panel W after theturnover is located downstream of the center of the liquid crystal panelW before the turnover, and the liquid crystal panel W does not go backwhen turned over. The corner portion is intended to include not only acorner (vertex) of the liquid crystal panel W but also an area rangingwithin a predetermined distance from the corner.

When the liquid crystal panel W is turned over by such a method, theliquid crystal penal W is positioned out of the second linear feed pathP2 as shown by the broken lines in FIG. 6 after the turnover. Therefore,as indicated by the arrow D1 in FIG. 6, the liquid crystal panel W ispreferably transferred onto the second linear feed path P2 after theturnover. According to this feature, a linear feed path can be formedfor the liquid crystal panel W so that a compact manufacturing line canbe formed. Alternatively, after the turnover, the liquid crystal panel Wmay be fed parallel to the second linear feed path P2 without beingreturned onto the second linear feed path P2. In this case, since thereis no need to return the liquid crystal panel W to the second linearfeed path P2, the tact time can be reduced correspondingly.

In this example, the liquid crystal panel W is turned over about theaxis A1 so that the positional relationship between the long and shortsides of the liquid crystal panel W can be reversed, which makes itpossible to achieve the same effect by a single operation as in the casewhere the liquid crystal panel W is turned over and rotated,independently. This allows a reduction in the number of steps andsimplification of the apparatus. In addition, the tact time can bereduced.

In particular, the positional relationship between the long and shortsides of the liquid crystal panel W can be easily reversed only byturning over the liquid crystal panel W about the axis A1 inclined by45° with respect to the feed direction. This allows furthersimplification of the apparatus and a further reduction in the tacttime.

Also when the liquid crystal panel W is turned over about the axis A1passing through a corner portion of the liquid crystal panel W, theliquid crystal panel W can be prevented from interfering with the liquidcrystal panel W-feeding line (such as a feeding mechanism includingcomponents of the panel feeding line L2, such as rollers) during theturnover of the liquid crystal panel W. Therefore, since there is noneed to vertically change the level of the liquid crystal panel W beforeand after the turnover, the tact time can be reduced correspondingly.

FIG. 8 is a schematic perspective view showing another example of themethod of turning over the liquid crystal panel W using the panelturning mechanism 200. In the panel turning mechanism 200, for example,the same structure as shown in FIG. 7 may be used to form the mechanismfor supporting the liquid crystal panel W, but it is non-limiting, andany of various other structures may be used.

In this embodiment, the liquid crystal panel W is turned over about anaxis A2 not parallel to any of the long and short sides of the liquidcrystal panel W. The axis A2 is inclined by 45° from the direction offeeding of the liquid crystal panel W along the second linear feed pathP2 to the direction parallel to the surface of the liquid crystal panelW.

In the example shown in FIG. 8, the liquid crystal panel W is turnedover about the axis A2 passing through the central portion of the liquidcrystal panel W. The axis A2 preferably passes through the center (thepoint of intersection of the two diagonal lines) of the liquid crystalpanel W, but may pass through a position deviating by a predetermineddistance from the center. In this example, the axis A2 passes throughthe central portion of the liquid crystal panel W, and therefore, asindicated by the broken lines in FIG. 8, the position of the liquidcrystal panel W is not horizontally shifted from the second linear feedpath P2 after the turnover, but to prevent the liquid crystal panel Wfrom interfering with the feeding line (for example, the feedingmechanism including components of the panel feeding line L2, suchrollers), the liquid crystal panel W is elevated (as indicated by thearrow D2 in FIG. 8) to a certain level different from the level at whichthe liquid crystal panel W is transported, and then the liquid crystalpanel W is turned over about the axis A2 passing through the liquidcrystal panel W, which is followed by lowering the liquid crystal panelW as indicated by the arrow D3.

In this example, the liquid crystal panel W is turned over about theaxis A2 so that the positional relationship between the long and shortsides of the liquid crystal panel W can be reversed, which makes itpossible to achieve the same effect by a single operation as in the casewhere the liquid crystal panel W is turned over and rotated,independently. This allows a reduction in the number of steps andsimplification of the apparatus. In addition, the tact time can bereduced.

In particular, the positional relationship between the long and shortsides of the liquid crystal panel W can be easily reversed only byturning over the liquid crystal panel W about the axis A2 inclined by45° with respect to the feed direction. This allows furthersimplification of the apparatus and a further reduction in the tacttime.

It is also possible to prevent horizontal displacement of the positionof the center of the liquid crystal panel W during the turnover of theliquid crystal panel W. Therefore, since there is no need tohorizontally move or return the liquid crystal panel W to the originalposition after the turnover, the tact time can be reduced accordingly.

FIG. 9 is a schematic perspective view showing a further example of themethod of turning over the liquid crystal panel W using the panelturning mechanism 200. In the panel turning mechanism 200, for example,the same structure as shown in FIG. 7 may be used to form the mechanismfor supporting the liquid crystal panel W, but it is non-limiting, andany of various other structures may be used.

In this embodiment, the liquid crystal panel W is turned over about asingle axis A3 that is not parallel to any of the long and short sidesof the liquid crystal panel W. The axis A3 is inclined by 45° from thedirection of feeding of the liquid crystal panel W along the secondlinear feed path P2 to the direction parallel to the surface of theliquid crystal panel W.

In the example shown in FIG. 9, the liquid crystal panel W is turnedover about the axis A3 not passing through the liquid crystal panel W.The axis A3 preferably extends parallel to the surface of the liquidcrystal panel W, more preferably extends in the same plane as thesurface of the liquid crystal panel W. When the liquid crystal panel Wis turned over by such a method, the liquid crystal penal W ispositioned out of the second linear feed path P2 as shown by the brokenlines in FIG. 9 after the turnover. Therefore, as indicated by the arrowD4 in FIG. 9, the liquid crystal panel W is preferably transferred ontothe second linear feed path P2 after the turnover. According to thisfeature, a linear feed path can be formed for the liquid crystal panel Wso that a compact manufacturing line can be formed. Alternatively, afterthe turnover, the liquid crystal panel W may be fed parallel to thesecond linear feed path P2 without being returned onto the second linearfeed path P2. In this case, since there is no need to return the liquidcrystal panel W to the second linear feed path P2, the tact time can bereduced correspondingly.

In this example, the liquid crystal panel W is turned over about theaxis A3 so that the positional relationship between the long and shortsides of the liquid crystal panel W can be reversed, which makes itpossible to achieve the same effect by a single operation as in the casewhere the liquid crystal panel W is turned over and rotated,independently. This allows a reduction in the number of steps andsimplification of the apparatus. In addition, the tact time can bereduced.

In particular, the positional relationship between the long and shortsides of the liquid crystal panel W can be easily reversed only byturning over the liquid crystal panel W about the axis A3 inclined by45° with respect to the feed direction. This allows furthersimplification of the apparatus and a further reduction in the tacttime.

Also when the liquid crystal panel W is turned over about the axis A3not passing through the liquid crystal panel W, the liquid crystal panelW can be prevented from interfering with the liquid crystal panelW-feeding line (such as a feeding mechanism including components of thepanel feeding line L2, such as rollers) during the turnover of theliquid crystal panel W. Therefore, since there is no need to verticallychange the level of the liquid crystal panel W before and after theturnover, the tact time can be reduced correspondingly. It should benoted that to reduce the tact time more effectively, the axis A3 ispreferably as close to the liquid crystal panel W as possible.

FIG. 10 is a schematic perspective view showing a further example of themethod of turning over the liquid crystal panel W using the panelturning mechanism 200. In the panel turning mechanism 200, for example,the same structure as shown in FIG. 7 may be used to form the mechanismfor supporting the liquid crystal panel W, but it is non-limiting, andany of various other structures may be used.

In this embodiment, the liquid crystal panel W is turned over about anaxis A4 passing through the central portion of the liquid crystal panelW in a manner similar to that shown in FIG. 8, except that the liquidcrystal panel W is not kept horizontal as shown in FIG. 8 when elevatedbut inclined with respect to the horizontal direction as indicated bythe arrow D5 in FIG. 10 when elevated and that the liquid crystal panelW is turned over in the inclined state and then lowered as indicated bythe arrow D6.

FIG. 11 is a schematic perspective view showing a further example of themethod of turning over the liquid crystal panel W using the panelturning mechanism 200. In the panel turning mechanism 200, for example,the same structure as shown in FIG. 7 may be used to form the mechanismfor supporting the liquid crystal panel W, but it is non-limiting, andany of various other structures may be used.

In this embodiment, the liquid crystal panel W is turned over about anaxis A5 passing through a corner portion of the liquid crystal panel Win a similar manner to that shown in FIG. 6, except that the liquidcrystal panel W is displaced from the second linear feed path P2 asindicated by the arrow D7 in FIG. 11 before the turnover and then turnedover so that it can be transferred onto the second linear feed path P2,instead of the process shown in FIG. 6, which includes turning over theliquid crystal panel W so that it is displaced from the second linearfeed path P2 and then transferring it onto the second linear feed pathP2.

FIG. 12 is a schematic perspective view showing a further example of themethod of turning over the liquid crystal panel W using the panelturning mechanism 200. In the panel turning mechanism 200, for example,the same structure as shown in FIG. 7 may be used to form the mechanismfor supporting the liquid crystal panel W, but it is non-limiting, andany of various other structures may be used.

In this embodiment, the liquid crystal panel W is turned over about anaxis A6 not passing through the liquid crystal panel W in a similarmanner to that shown in FIG. 9, except that the liquid crystal panel Wis displaced from the second linear feed path P2 as indicated by thearrow D8 in FIG. 12 before the turnover and then turned over so that itcan be transferred onto the second linear feed path P2, instead of theprocess shown in FIG. 9, which includes turning over the liquid crystalpanel W so that it is displaced from the second linear feed path P2 andthen transferring it onto the second linear feed path P2.

FIG. 13 is a schematic perspective view showing a further example of themethod of turning over the liquid crystal panel W using the panelturning mechanism 200. In the panel turning mechanism 200, for example,the same structure as shown in FIG. 7 may be used to form the mechanismfor supporting the liquid crystal panel W, but it is non-limiting, andany of various other structures may be used.

In this embodiment, the liquid crystal panel W is turned over about anaxis A4 passing through the central portion of the liquid crystal panelW in a similar manner to that shown in FIG. 8, except that the liquidcrystal panel W is not elevated as shown in FIG. 8 but horizontallymoved to a position where it does not interfere with the feeding line(for example, a feeding mechanism including components of the panelfeeding line L2, such rollers) as indicated by the arrow D9 in FIG. 13,turned over at that position, and then moved onto the linear feed pathP2 as indicated by the arrow D10.

The above are mere examples of the method of turning over the liquidcrystal panel W using the panel turning mechanism 200, and the liquidcrystal panel W may be turned over in various other modes.

FIGS. 14A to 14E are diagrams showing examples of how the panel turningmechanism 200 comes into contact with the surface of the liquid crystalpanel W when it supports the liquid crystal panel W. In the panelturning mechanism 200, the part to be in contact with the surface of theliquid crystal panel W is preferably made of a material that is smoothand less likely to scratch the liquid crystal panel W, such as resin orrubber. It will be understood that the contact modes described belowwith reference to FIGS. 14A to 14E are mere examples and the panelturning mechanism 200 to be used may come into contact with the surfaceof the liquid crystal panel W in any of various other modes.

FIG. 14A is a perspective view showing an example where the panelturning mechanism 200 comes into surface-contact with the surface of theliquid crystal panel W to support it. FIG. 14A shows a structure havinga plate-shaped component 201 for holding both surfaces of the liquidcrystal panel W. Such a structure is non-limiting, and the mechanism maybe configured to use any other component for making surface-contact withthe surface of the liquid crystal panel W.

FIG. 14B is a perspective view showing an example where the panelturning mechanism 200 comes into line-contact with the surface of theliquid crystal panel W to support it. FIG. 14B shows a structure havinga network component 202 for holding both surfaces of the liquid crystalpanel W. Such a structure is non-limiting, and the mechanism may beconfigured to use any other component for making line-contact with thesurface of the liquid crystal panel W.

FIGS. 14C and 14D are side views showing examples where the panelturning mechanism 200 comes into point-contact with the surface of theliquid crystal panel W. FIG. 14C shows a structure having a plurality oftapered projections 203 for coming into contact with and holding bothsurfaces of the liquid crystal panel W. FIG. 14D shows a structurehaving rotatable bearings 204 for coming into contact with and holdingboth surfaces of the liquid crystal panel W. It will be understood thatsuch structures are non-limiting, and the mechanism may be configured touse any other component for making point-contact with the surface of theliquid crystal panel W.

FIG. 14E is a side view showing an example where the panel turningmechanism 200 has a large number of surfaces coming into contact withthe surface of the liquid crystal panel W to support it. FIG. 14E showsa structure having a plurality of projections 205 with end faces forcoming into contact with and holding both surfaces of the liquid crystalpanel W. Such a structure is non-limiting, and the mechanism may beconfigured to use any other component for making multi-surface-contactwith the surface of the liquid crystal panel W.

FIGS. 15A to 15I are schematic plan views showing examples of which partof the liquid crystal panel W is supported by the panel turningmechanism 200. The part of the liquid crystal panel W supported by thepanel turning mechanism 200 may be the whole of the surface of theliquid crystal panel W or only part of the surface of the liquid crystalpanel W, for example, as shown in FIGS. 15A to 151. The liquid crystalpanel W may also be supported in any of various other modes as long asthe liquid crystal panel W is not thrown from the panel turningmechanism 200 during the turnover or not overloaded during the turnover.

FIG. 15A shows an example where both long sides and both short sides ofthe liquid crystal panel W are supported. FIG. 15B shows an examplewhere in addition to the feature shown in FIG. 15A, the liquid crystalpanel W is further supported along the two diagonal lines. FIG. 15Cshows an example where in addition to the feature shown in FIG. 15A, theliquid crystal panel W is further supported along one of the diagonallines. FIG. 15D shows an example where in addition to the feature shownin FIG. 15A, the liquid crystal panel W is further supported at acenter-facing part along the longitudinal direction. FIG. 15E shows anexample where in addition to the feature shown in FIG. 15A, the liquidcrystal panel W is further supported at a center-facing part along thetransverse direction. FIG. 15F shows an example where in addition to thefeature shown in FIG. 15A, the liquid crystal panel W is furthersupported at center-facing parts along the longitudinal and transversedirections. FIG. 15G shows an example where the liquid crystal panel Wis supported at one of the long sides and one of the short sides andalong one of the diagonal lines. FIG. 15H shows an example where theliquid crystal panel W is supported at one of the long sides and one ofthe short sides and along the other of the diagonal lines. FIG. 15Ishows an example where the liquid crystal panel W is supported only atone of the long sides and one of the short sides. In this case, thesupporting area facing around the long and short sides is preferablylarger than that in the case shown in FIG. 15A where the liquid crystalpanel W is supported at both long sides and both short sides.

As described above, the liquid crystal panel W may be supported at foursides including both long sides and both short sides (for example, asshown in FIGS. 15A to 15F) or supported at two sides including one longside and one short side (for example, as shown in FIGS. 15G to 15I).Although not shown, the liquid crystal panel W may be supported at threesides including both long sides and one short side or including one longside and both short sides.

In a more preferred structure, two sides including one long side and oneshort side should be supported (for example, as shown in FIGS. 15G to15I). According to such a structure, the liquid crystal panel W can besuccessfully supported, not depending on the size of the liquid crystalpanel W. Specifically, the structure configured to support end facesalong both long sides or along both short sides (for example, as shownin FIGS. 15A to 15F) cannot support the liquid crystal panel W, when thesize of the liquid crystal panel W is larger than the distance betweenthe long side-supporting parts 201 or the short side-supporting parts202. In contrast, as illustrated in FIGS. 15G to 15I, the structureconfigured to support only an end face along one long side and an endface along one short side can successfully support the liquid crystalpanel W of even a larger size. Therefore, such a structure makes itpossible to turn over different size liquid crystal panels W in the samepanel turning mechanism 200.

In addition, the structure configured to support end faces along bothlong sides or along both short sides (for example, as shown in FIGS. 15Ato 15F) may cause a force to act on the liquid crystal panel W from theopposed long side-supporting parts 201 or the opposed shortside-supporting parts 202, so that an excessive load may be applied tothe liquid crystal panel W to cause cracking, chipping or bending of theliquid crystal panel W. In contrast, as illustrated in FIGS. 15G to 15I,the structure configured to support only an end face along one long sideand an end face along one short side can prevent such problems. Thisadvantageous effect becomes more significant as the size of the liquidcrystal panel W increases.

In addition, when the liquid crystal panel W is supported only at an endface along one long side and at an end face along one short side asshown in FIGS. 15G to 15I, the long side-supporting part 201 and theshort side-supporting part 202 only have to be in contact with these endfaces, so that the time required to support the liquid crystal panel Wcan be reduced as much as possible, which can increase the productionefficiency. In contrast, the structure configured to support end facesalong both long sides or along both short sides (for example, as shownin FIGS. 15A to 15F) requires a process including bringing the longside-supporting part 201 or the short side-supporting part 201 intocontact with one end face along one long or short side and then bringingthe long side-supporting part 201 or the short side-supporting part 202into contact with the other end face along the other long or short side,which increases the number of steps and the time required to support theliquid crystal panel W.

When the liquid crystal panel W is supported only at an end face alongone long side and at an end face along one short side as shown in FIGS.15G to 15I, it is preferred that as in the configuration shown in FIG.7, the long side-supporting part 201 should come into contact with onlyan end face along a closer-to-axis-A1 long side of the liquid crystalpanel W to support the liquid crystal panel W, and the shortside-supporting part 202 should come into contact with only an end facealong a closer-to-axis-A1 short side of the liquid crystal panel W tosupport the liquid crystal panel W. In this case, the liquid crystalpanel W can be turned over while the liquid crystal panel W is supportedat an end face along one long side and at an end face along one shortside by the long side-supporting part 201 and the short side-supportingpart 202, respectively, from the lower side, so that the liquid crystalpanel W is prevented from interfering with the liquid crystal panelW-feeding line (such as a feeding mechanism including components of thepanel feeding line L2, such as rollers).

EXAMPLES

A description is given below of the results of the measurement of theincidence of cracking or chipping of liquid crystal panels W in a casewhere the panel turning mechanism 200 configured as shown in FIG. 7 wasused to turn over liquid crystal panels W of a large size (such as 32inches or more) about the axis A1 not parallel to any of the long andshort sides of the liquid crystal panel W (oblique axis turnover method)and in a case where liquid crystal panels W were turned over about anaxis parallel to the long side of the liquid crystal panel W (lateralaxis turnover method).

Example 1

In Example 1, 32-inch liquid crystal panels W were turned over by theoblique axis turnover method. As a result, the incidence of cracking orchipping of the liquid crystal panels W was 1%.

Example 2

In Example 2, 40-inch liquid crystal panels W were turned over by theoblique axis turnover method. As a result, the incidence of cracking orchipping of the liquid crystal panels W was 1%.

Example 3

In Example 3, 65-inch liquid crystal panels W were turned over by theoblique axis turnover method. As a result, the incidence of cracking orchipping of the liquid crystal panels W was 2%.

Example 4

In Example 4, 82-inch liquid crystal panels W were turned over by theoblique axis turnover method. As a result, the incidence of cracking orchipping of the liquid crystal panels W was 3%.

Comparative Example 1

In Comparative Example 1, 32-inch liquid crystal panels W were turnedover by the lateral axis turnover method. As a result, the incidence ofcracking or chipping of the liquid crystal panels W was 1%.

Comparative Example 2

In Comparative Example 2, 40-inch liquid crystal panels W were turnedover by the lateral axis turnover method. As a result, the incidence ofcracking or chipping of the liquid crystal panels W was 2%.

Comparative Example 3

In Comparative Example 3, 65-inch liquid crystal panels W were turnedover by the lateral axis turnover method. As a result, the incidence ofcracking or chipping of the liquid crystal panels W was 15%.

Comparative Example 4

In Comparative Example 4, 82-inch liquid crystal panels W were turnedover by the lateral axis turnover method. As a result, the incidence ofcracking or chipping of the liquid crystal panels W was 23%.

From the results of the measurement, it has been found that theincidence of cracking or chipping of liquid crystal panels W is higherwhen the liquid crystal panels W of the same size are turned over by thelateral axis turnover method than when they are turned over by theoblique axis turnover method. In particular, as the size of the liquidcrystal panels W increased (for example, to 40 inches or more), theoccurrence of cracking or chipping of the liquid crystal panels W becamemore frequent. The measurement results are summarized in Table 1 below.

TABLE 1 Incidence (%) of panel Panel size cracking or Method (inch)chipping Example 1 Oblique axis 32 1 Example 2 turnover 40 1 Example 365 2 Example 4 82 3 Comparative Lateral axis 32 1 Example 1 turnoverComparative 40 2 Example 2 Comparative 65 15 Example 3 Comparative 82 23Example 4

What is claimed is:
 1. A system for manufacturing a liquid crystal display device by bonding sheet pieces of optical functional films comprising polarizing films to both surfaces of a rectangular liquid crystal panel, comprising: a panel turning mechanism for turning over the liquid crystal panel after one of the sheet pieces of optical functional films is bonded to the liquid crystal panel and before another of the sheet pieces of optical functional films is bonded thereto, wherein the panel turning mechanism has: a long side-supporting part for supporting the liquid crystal panel by coming into contact with an end face along at least one long side of the liquid crystal panel; and a short side-supporting part for supporting the liquid crystal panel by coming into contact with an end face along at least one short side of the liquid crystal panel, and the panel turning mechanism turns over the liquid crystal panel about a single axis neither parallel to the long side of the liquid crystal panel nor to the short side of the liquid crystal panel in such a manner that the positional relationship between the long and short sides of the liquid crystal panel is reversed.
 2. The system according to claim 1, wherein the long side-supporting part comes into contact with only an end face along one long side of the liquid crystal panel to support the liquid crystal panel, and the short side-supporting part comes into contact with only an end face along one short side of the liquid crystal panel to support the liquid crystal panel.
 3. The system according to claim 2, wherein the long side-supporting part comes into contact with only an end face along a long side of the liquid crystal panel to support the liquid crystal panel, wherein the long side is closer to the single axis, and the short side-supporting part comes into contact with only an end face along a short side of the liquid crystal panel to support the liquid crystal panel, wherein the short side is closer to the single axis.
 4. The system according to claim 1, wherein the panel turning mechanism has a both surface-contact part for coming into contact with at least part of both surfaces of the liquid crystal panel.
 5. The system according to claim 1, wherein the panel turning mechanism turns over the liquid crystal panel about an axis inclined by 45° from a direction of feeding of the liquid crystal panel to a direction parallel to the surface of the liquid crystal panel.
 6. The system according to claim 1, which is for manufacturing the liquid crystal display device by a process comprising feeding optical functional films from first and second continuous rolls with different widths, respectively, which are each formed by winding, into a roll, a long optical functional film comprising a polarizing film, transversely cutting the optical functional films to form sheet pieces of the optical functional films, and bonding the sheet pieces to both surfaces of the rectangular liquid crystal panel.
 7. The system according to claim 1, which is for manufacturing the liquid crystal display device by a process comprising feeding sheet pieces of optical functional films and carrier films from first and second continuous rolls with different widths, respectively, which are each formed by winding, into a roll, a laminate comprising a carrier film and sheet pieces of an optical functional film comprising a polarizing film, peeling off the sheet pieces of the optical functional films from the carrier films, and bonding the sheet pieces to both surfaces of the rectangular liquid crystal panel. 